Oceanography slide 2+3
Card Set Information
Oceanography slide 2+3
Modern Methods for Measuring the Bathymetry of the Ocean floor:
Echo sounding and Swath Mapping - a method using powerful sound pulses.
Satellite Altimetry - Satellites can measure the height of the ocean very accurately.
the mid-ocean ridges are essentially a long continuous under water ____.
shallow and relatively flat region overlying continental crust.
Transition region between continental and oceanic crust is...
Thick prism of sediment deposited at base of Continental slope
Broad flat plain covered with sediment, overlying rugged ocean floor.
Active margins are located near the edge of _____ plates. Active margins are the site of ______ and _____ activity.
converging. volcanic, earthquake
_____ can only occur where slopes are relatively steep. Upon reaching the flat Abyssal floor _(answer above)_ ____ and ____ their sediment.
Turbidity currents, TB, weaken and deposit
_______ are volcanic projections from the ocean floor that do not rise ______. flat topped seamounts eroded by wave action are called ______.
Seamounts; above sea level; guyots
Symmetric ripples are formed by.....
Asymmetric currents are currents formed by.....
Classification of Sediment and its source
Terri- Erosion of land, volcanic eruptions, blwon dust
Bio- Organic; acummulation of hard parts of some marine organisms
Hydro- Precipitation of dissolved minerals from water, often by bacteria
Cosmogenous - dust from space, meteorite debris
What pathways do sediments travel to reach the ocean?
Fluvial Inputs - Rivers dischange Sediment into the Ocean
Aeolian inputs - winds carry sediments from the continents into the ocea
Biological inputs - marine organisms die and sink to the bottom
Authigenic inputs - sediments that are formed in the oceans. Mainly metal rich materials near hydrothermal vents
Most deep sea clays derived from _________ transport.
_______ can transport terrigenous sediment down the continental slope.
Any sediment that is > 30% biologically- derived materia is called a ....?
Calcium Carbonate solubility increases with ______ and _____.
increasing pressure; decreasing temperature
The depth below which carbonate sediments will not accumulate is called...? and why doesn't "marine snow" read.
Carbonate Compensation Depth (CCD)
Below CCB, water holds more CO
which results in more carbonic acid, which dissolves CaCO
What does Calcium Carbonate Content tell us?
1) North Pacific is generally deeper than North Atlantic
2) Mid-Ocean ridges are shallower than abyssal plain.
Silica preservation mainly reflects _____?
Hydrogenous sediments _____ directly from seawater.
What are most common hydrogenous sediments?
manganese nodules, include evaporites and oolites
Biogenic Sediment are? 3 caterogies
Carbonate Ooze, siliceous ooze and biogenic material.